God made a covenant with Moses and his people, giving them the law and declaring blessings for obedience and curses for disobedience of that Law. Like all other Old Testament promises by God, this one is fulfilled in Jesus Christ, who took our curses on the cross so that we would be blessed in Him forever!
The Mosaic Covenant was fulfilled in Jesus Christ as He went to the cross to become cursed for our sins as we became blessed for His obedience. Something to be joyful about!! Be blessed by this short message!